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<table width="100%" summary="page for Dactyl"><tr><td>Dactyl</td><td align="right">R Documentation</td></tr></table>

<h2>
Edgeworth's counts of dactyls in Virgil's Aeneid
</h2>

<h3>Description</h3>


<p>Edgeworth (1885) took the first 75 lines in Book XI of
Virgil's <EM>Aeneid</EM> and classified each of the first four &quot;feet&quot; of the line 
as a dactyl (one long syllable followed by two short ones) or not.
</p>
<p>Grouping the lines in blocks of five gave a 4 x 25 table of counts,
represented here as a data frame with ordered factors, <code>Foot</code> and
<code>Lines</code>. Edgeworth used this table in what was among the first
examples of analysis of variance applied to a two-way
classification.
</p>


<h3>Usage</h3>

<pre>data(Dactyl)</pre>


<h3>Format</h3>


<p>A data frame with 60 observations on the following 3 variables.
</p>

<dl>
<dt><code>Foot</code></dt><dd><p>an ordered factor with levels <code>1</code> &lt; <code>2</code> &lt; <code>3</code> &lt; <code>4</code></p>
</dd>
<dt><code>Lines</code></dt><dd><p>an ordered factor with levels <code>1:5</code> &lt; <code>6:10</code> &lt; <code>11:15</code> &lt; <code>16:20</code> &lt; <code>21:25</code> &lt; <code>26:30</code> &lt; <code>31:35</code> &lt; <code>36:40</code> &lt; <code>41:45</code> &lt; <code>46:50</code> &lt; <code>51:55</code> &lt; <code>56:60</code> &lt; <code>61:65</code> &lt; <code>66:70</code> &lt; <code>71:75</code></p>
</dd>
<dt><code>count</code></dt><dd><p>number of dactyls</p>
</dd>
</dl>



<h3>Source</h3>


<p>Stigler, S. (1999)
<EM>Statistics on the Table</EM>
Cambridge, MA: Harvard University Press, table 5.1.
</p>


<h3>References</h3>


<p>Edgeworth, F. Y. (1885).
On methods of ascertaining variations in the rate of births, deaths and marriages.
<EM>Journal of the [Royal] Statistical Society</EM>, 48, 628-649.
</p>


<h3>Examples</h3>

<pre>
data(Dactyl)

# display the basic table
xtabs(count ~ Foot+Lines, data=Dactyl)

# simple two-way anova
anova(dact.lm &lt;- lm(count ~ Foot+Lines, data=Dactyl))

# plot the lm-quartet
op &lt;- par(mfrow=c(2,2))
plot(dact.lm)
par(op)

# show table as a simple mosaicplot
mosaicplot(xtabs(count ~ Foot+Lines, data=Dactyl), shade=TRUE)
</pre>


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